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UNiTED e STATES Erice@ i GEORGE F. CHAMPNEY, DF TAUNTON, MASSACHUSETTS,ASSIGNOR OF THREE-FIFTHS TO ALFRED-H. HARRISON, OF LONDON, ENGLAND.

ART oF MAKING ollas.`

SPECIFICATION forming' part 0f Letters Patent No. 499,820, dated June20, 1893.

Application tiled December Il, 1889. Serial No. 332.533. (No model.)

To all whom it muy concern:

',Be it known that I, GEORGE F. CHAMPNEY, a citizen of the UnitedStates,residing at Taunton,county of Bristol, and State of Mas- .to the valueof the process. stacle referred to` is the liability of the patrice themaking and also by cutting .from a solid steel block al patriceI inrelief, which is then pressed byslow degrees and repeated blows intothe-die block. Both methods are very tedious and costly and neitherproduces perfect work, since the traces of the tools are necessarilypresent. It has also been proposed to attach the patrice to a drophammer, place the block 4of steel While-hot under it, and force thepatrice into the block by dropping the hammer. The last mentionedprocess has had the advantage of. much greater speed and economy thanthose before mentioned, but is 4open to t`wo considerable objections.The `first of these is that where the work is delicate vand difficultthe die is likely'to'. be imperfect.

Thus, for instance, when figures portrayed' are sharp, particularlyabout the outer edge of its face, the angles are likely to'be imper-4fectly reproduced in the die block and the` distinctness ofthe originalthus lost. As lineA work abounds in parts thusdifticult of reproductionthis obstacle has been a seriousone The second obwhen made from castiron or other fragile or soft metal, to be broken or crushed by'theforce of the blow and thus fail to effectthe. desired impression.

My present inventionis in the nature'or` an improvement upon the lastmentioned process and is based upon the discovery thatthe obstaclesjuststated can be avoided and theI process perfected by giving to thepatrice-at .the moment 4ot ts'impact upon the dieblock.

an exceptionally high degree of speed. This" A vhigh Yvelocity secures."a' result which, in the perfection and certainty of the 'die produced,is new and which cannot be reached by merely Hitherto these dies havebeen increasing' the power of the blow by adding to the weight of thehammer. The new rewhen formed from cast iron, or from a comparativelysoft metal, such as bronze, gold, -silver or even copper, to be brokenor crushed by contact with the dieblock,is avoided, and also that them'ost delicate parts of themos't difficult and nest work are brolughtout'v ac-I curately i-n the die block and aperfect reproduction ofthepatrice secured,ths beingtrue even where the relief andy intaglios ofthe patrice are very sharp and deep and finely drawn. The patrice passesso rapidly into the steel of the die block that it 'does not reit, theblow expending itself 'for the most part in the striking of the extendedbase of the patrice against the marginal top of the die block; and thehigh velocity of the patrice not giving suicient time for its breaking down Perfect dies are thus securedwith great certainty andcomparativelyslight cost even for the most complicated and delicatework.

The requiredvelocity may be given to the practical 'and eicient meansknown to me is that of a fall hammerdropping from a suiciently highelevation.v The velocity which must be given to the patrice at themoment of suits, and which -I' referto herein as a high degree of speed,is a' velocity of from aboutA twenty-five feet per second up toseventy-ve and Yone hundred, or even more', feetper second; and thislvelocity may befsecured by a ten feet upward. I A,

' In the'process above'referred to, upon which the present invention isafn improvement, it was proposed to use the/ordinary drop hammeremployed in the arts having a fall of from two to six feet. The highdegree of speed necessary to the practicey of my. invention drop hammeras' lheretofore commonly employed in' the arts; and I have found" itnecessary to obtain specially constructed drop patricein any desiredmanner, but the mostl hammers of much more than the usual'height. vIthave usedwith excellentresultsdrop ham- ./r'/

lsult is that all liability of the patrice, even v ceive enough of theforce of the blow to injure away from the angles and sharp corners.

impact in orderto secure my improved re-l drop hammer having a clearfall/of from about i 9o y therefore cannot bjc/secured by the useof. the

face of the die block, now known or hereafter 15. devised, may b'eemployed for the purpose. The most practicable and-best means known tomeconsist in covering the face o't the die blockwith a close-fittingcap', and inclosing the die block and cap in an air-tight, close- -zofitting casin g of suitable material before placing itin the-furnace.The die block thus protected and placed in the furnace is brought tosuch a degree of heat as desired. I find that the best degree of heatfor this purpose is a white or welding heat, but other degrees ofheatmay be employed. Theheated die block is then taken from the furnace, theinclosing hood is removed, and the die block is placed under the hammer;the .elose-itting 3o cap is then removed and the impactof the patrice iseffected before exposure to the atmosphere can cause oxidation-of thesurface of the die block. Sometimes it is possible to dispense with theinner .close-fitting cover where the reliefs are low and the surfacesplain, so that. the effects of oxidation can be.

removed from the die block lby the use of tools. Ido' not limit myselfin carrying out the above mentioned operations to the use of 4o avpatrice, made of any particular material or made in any particularmanner. I prefer to make the patrice by casting in a suitable mold froma form or pattern, using any suit;

, able metal. The l'best 'metal known to me for the purpose is iron,.including under that term steel. I prefer, to use cast iron, addingthereto while molten about six per cent. of steel chips. -Theprocesswhich is the subject-matter of my present application may bepracticed 5o.'with very many forms of apparatus, and I .do

not confine the practice of the process to thev use of anyparticularform or construction. thereof.- I will however describe the arrest,lsuitable form of apparatus now known to me' for the purpose. l

l In the drawings annexed .to this specificaF A tion and forming`ari-part thereof, Figure 1' shows vin section a. die block and theswage "or die holder inwhich the die block is held 6o while receivingthe impression, and in eleva-v tion thehammer carrying the patrice andthe guides between whichit works up and down,

the position of the parts being thatimmeditelynfollowing a 'blow of 'thehammer. Fig. 2 is a side view'of the samepartly'insection on line 2.-,2,Fig.3. Fig.3 isa plan view 'of the die holder and die block partly insection on line 3-3 of Fig. 2. Fig.- 4 represent-s mechanism hereinafterdescribed for catching the hammer on the rebound, the clutches beingshown withdrawn from that position in which they engage with theratchets. Figs. 5 and Gare respectively longitudinal' and cross verticalsections, on an enlarged scale, of a die block, its cap and casing. Y

'The die block A is,.as I have stated, preferably of steel o r ironfaced with steel, and is of rectangular orc'ircular or other desiredform. The top surface maybe fiat, butI prefer to have it made with acentral projection onfullness, as shown, sloping from the center topoints'near the edges of 'the block. The object of this fullness isy tosecure a greater degree of adaptability in the metal ofthe die block tothe shape of the patrice than would v be possible if the' surface of thedie block were plain. being upon the apex of the fullness of the-dieblock, this part' of the die block is free to adapt itself totheeonliguration of the patrice and to completely fill all `its recessesbefore.

the movement of the patrice is arrested by the contact of itsiiatsurface with the face of the die block.- Moreover, lthisfullness inthe die block permits the air to be driven from The first impact of thepatrice the center outward frombetween thepatrice and the die block,preventing the inclosure of air between approaching surfaces,` theeffeet of which would be, if it occurred,to keep the metal of the diefrom following into the sharp angles and recesses of the patrice andwould more or less d ull the impression,- preventing the production of asharply defined die. The block is provided with a cap a so shaped-as toclosely fit its surface andis, thus' protected, inclosed injan air-tightcaseof appro'priatefmaterial and shape. For this case I prefer to usesci ne refractory'material, such as plnmbago,.formed or pressed 'intoshape. t

The form of case shown herein consists, (see Fig. 5) of a. plate b onwhich the die rests, and a cover c inclosingthe die block andrestingupon' the plate bin such manner as to exclude air.

The channel tool or'die holder in which the die block'is held whilebeing impressed consists, in the preferred form 'which I have shownlll-5 I.

v herein, of a solid block of steel d of suitable 'IA size, for instancethree and a half feet long by .Y

twelve or thirteen inches wide and eight or nine inches high, in whichis planed a channel Ig about four inches wide and half the -1 depth ofblock, vto receive thedi block.

Steel lreinforcingstraps e embracing the sides of the' block are shrunkon -and fastened by steel -bolts f passing-through the .body of.theblock. 'Other large bolts, four of which are shown, pass through thelower part of theblock at intervals ofits length for the pur-` poseofstrengthening it against. th'e tendency to split longitudinally underthe stress of t-he Ablow ol` the hammer. At each end', ,of the' blockand just above thelevel of thebottom izov -of the channel arecuttwe'slightly tapering fall and vice versa.

about fifteen feet.

key-ways h adapted to receive the tapering keys 'k which are somewhatlonger than the width of the block and which form end bearings for thedie block, or for packing pieces between the die block and the keys andare driven in to wedge the die block in place. These packing pieces z'are used for the purpose of adaptingthe` die holder to dies of dit'-ferent lengths. Packing pieces may be also inserted lengthwise of thedies to permit the die holder to .be used for die blocks of differrentwidths. For certainty in centering the die block under the hammer, it isconvenient to first drive one of the channel keys home, place the properamount of packing between this channel piece and the die block to bringit into its prper position under the hammer, drop in the die block andwedge the die block in piace by driving in the other key against asuitable amount of packing interposed between the key and die block.Great strength in the die holder and tight and secure wedging ot the dieblock are desirable on account of the enormous spreading force exertedupon the die block by the blow of the hammer. It is in order to hold themetal of the die block up to the patrice, and thus insure 'a perfectimpression,at the same time avoiding distortion of the die block,that'the die block is so tightly and powerfullyfconined. Y

The block d stands upon a suitable foundation between two-upright guidesm, n, between which the -hammer o slides up and down, suitable powerapparatus being provided for raising the hammer, and a suitable I tripoperated from below'for permitting it to fall. The weightof 'the' hammerwill vary with `the character of the work .to. be done and the distanceit is caused to fall. Within 'certain limits reduction in the weight ofthe hammer maybe compensated by increased For ordinary light work, suchas making dies for scissors, hammer heads, wrenches and other smalltools, I prefer to fuse a hammer weighing Aabout one thousand poundsdropping from a height of The hammer preferably carries a hardened steelhammer block' p, adapted to enter the channelof the die holder, to thestriking face of which is attached the patrice in any suitable manner. Ifind it most. con venient to fasten the patrice detachably, so

that its connection with the hammer. may be as plaster of broken by theshock ot impact with the die block andthe patrice left resting on or inthe dieblock as the hammer recedes after the blow. This may b e done bythe use of a cement, such paris which is the best cement known to me forthe purpose, spreading the cement over the face of the hammer block in aplastic condition and applying thepatrice thereto; but the patrice maybe fastened to the hammer'blcck in any other suitable manner.

` It is very desirable in carrying out this process to provide meansforpreventing the hammer from making 'a double blow upon the die .shownin Fig. 1.

block. Theimpact of the hammer, when moving at high speed, upon the dieblock causes it to reboundand to fall back, striking the die block againwith vgreat force unless some means are provided for preventingthesecond descent of the hammer. The effect of such a second blow isfrequently to destroyrthe die cut by theiirst blow since it willsometimes happen that two such successive blowswill not be exactlycoincident with each other. This is the case where the patrice isattached permanently it is detachabiy affixed to it, as' by cement. Inthe latter case the patrice is sometimes partially pulled out of the dieblock before it is detached yfrom the hammer, so that, if struck by thehammer after the rebound, it would be liableto diverge from its originalimpression and spoil the die. The means which I preferably use forpreventing the second blow of the hammer are shown in Figs. 1, 2 and 4and consist of two ratchetbars q q', one attached to each of theuprights myn., and two clutches B pivoted upon bolts s siixedinthehamner and having on their lowerends teeth adapted -to mesh with theratchets. To the hammer face is fixed a vertical mandrel t, the ends ofwhich are held by clips luJ u. VAbout the mandrel is a cylinder E,the-head E' of' which has in it a hole through which the mandrel passes.The lower end of the cylinder lits loosely about a collar c, free toslide up and down on the mandrel. About the'mandrel is a spring a: heldunder a slight pressure, be-

tween the head of the cylinder and the collar.

Near the top of thezcylinder and on opposite sides are two external lugsy y. Eachof the clutches Bis provided with a pair of arms B B2. Thesearms B are so adjusted that when. their upper ends rest against the lugsy, y',

as shown in Fig.\4,the arms B2 support the collar 'v and compress thespring -The operationjof this device is asfollows: The clutches normallyrest vwith their arms B against the lugs y as shown in Fig. 4, in whichposition the teeth ou their iowerends cannot engage with the teeth'onthe ratchets q. When the hammer descends and vstrikes the die block themomentumof the cylinder E carries it downwardagainst the Vpressure otthe spring a: until the lugs y y release the arms B' and permit theclutches. to spring outward under the pressure ofthe spring actingthrough the collar u and the lower arms. B2, until the .parts assume theposition .Thelugs y y' are nowcaught under the upper hooked ends of armsB. The cylinder is thus and the clutches 'are forced outward and dragalong the teeth of the ratchets as the ham-v to the hammer, `and alsowhere IOC held in its depressed position,

mer continues to rise on its rebound, As"v soon as the 'hammer ceases toascend the'teeth o; the' clutches engage with' the teeth pfzthe ratchetsand preventa second descentfWhen the hammer 1s to be again raised' thelower ends ofthe clutches B are pressed ltogether,

i v the patrice to-th 'e hammer block is advanwhich does not require agreat exertion of force, and the cylinder E immediately returns to itsnormal place and locks the clutches l5 in the position shown in Fig. 1.Handles D are inserted in the lower ends-of the clutches for use inpressing the clutches together. \Vhi1e this is the preferred form ofapparatus for preventing a second blow upon' the dieblock I do notconfine myself to the use thereof, but may employ any apparatus suitablefor the purpose, or mayuse the hammer without such apparatus.

In practicing my invention with the described apparatus the cap aisfirst applied to the die block, the die block is then inclosed in thecasca-resting on the base b, and the incased die block is then Aplacedin the furnace and suitably heated. The die holder is then adjusted toreceive the .die block and the patrice isattached to the hammer block;the heatedA die block is removed from the furnace, the casing taken off,and the die block dropped into the die space prepared for it in the dieholder. The key is then driven home, wedging the die block between thepacking pieces. The cap a is removed and immediately the hammer istripped and drops, and the patrice is driven into the die block. Thehammer rebounds and is caught by the clutches, and there suspended untilit is againY raised. yWhere the patrice is attached to the hammer blockby cement the force of the blow destroys the cement and breaks theconnection; and the hammer block rises leaving'the patrice in the die.This method of attaching tageou'sfor a number of reasons; first, it isconvenient and permits'patrices of different lsizes to. becentered upon'the face of the hammer block. Again, it is desirable in` many cases toleave the patrice in the die until the latter v has cooled, so as toeffectually l Lprevent the access of" air to the surface of the 'diewhile hot.. This can bemore eectually done by leaving the patrice in thedie than by filling the die with powdered charcoal which is a method ofexcluding the air sometimes resorted to.

After the dieA is cold its surface may be brushed with a solution ofmuriatic trice as the equivalent of motion of a patrice against astationary die block.

An advantage of the process above set forth to which I wish to callparticular attention is the fact above'adverted to that the highveflocity of the patrice at the moment of impact makes itpossible topenetrate the steel die block with a patrice fo'rnled of metals verymuch softer and more fragile, and therefore more easily worked, than apatrice cut from rolled cast steel which must be employed where thepatrice is placed upon the die block iicult to make and much lesscostly, While at" the same time I obtain better results than can besecured by any other process.

' Certain features of the machine herein described are claimed in myapplications, Serial Nos. 333,357 and 435,478, filed December l1,

1889, and June 4, 1892, and are therefore not 1 claimed herein.

Having thus described my invention, what I claim, and desire to protectby Letters Patent, is-

Y 1. The process of making steel dies, which consists in preparing andheating a` suitable steel or iron and steel die block and causing thepatrice to move at a high f degree of speed as hereiubefore defined, andwhile so moving to strike thedie block and cut the die yat a singleblow, substantially as described.

steel or iron and steel, die block andpreparing-a patrice from a metalwhich is comparatively soft or capable of being readily brought to thedesired shape, as cast iron, and causing the patrice to move at a highdegree of speed as hereinbefore defined, and while so moving tostrike-the die block and cut the die at a single blow, substantially asset forth.

In testimony .whereof I have hereunto set vIO my hand in the presence oftwo subscribing l witnesses. i

. `Witnessesz f, J. J'. KENNEDY, EDWARD R. WOOD.

GEORGE F. oHA/lyvPNEY. y

